753 + LS1 setup

[Gonzo7]

Been trying to get my 753 to hook up & not slip. Impellers are all std brass 19's with S/S tips. Built up & new 2205 S/S wear rings. Still slips with wot from standstill and under load. 95mm insert in a flo pro nozzle. Pulls about 4400rpm wot but seems hooked up at top speed. Thinking I need a bullet impeller up front and looking for feedback on brand and pitch to suit. Holeshot and cruising more important than speed.
Thanks in advance.

[Ross Goldsack - JBNZ Immediate Past President]

I wonder if you have an air leak somewhere? Carbon seal, intake to delta or something like that.

[boon]

Bullet up front will sort it out. Not sure on pitch though... I ran a 18 degree but could probably have gone 19/20 or even 21. That’s where you need some good advice from someone like Bruce @ jetboat base.

Fine tune with nozzle inserts.

Scott 3 blade are the business but expensive (well they used to be)

[bbs 540]

Is your rev counter reading right 4400 rpm on three std 19's and a 95 nozzle seems low? bullet will help your lift and cav issue but at a price. Weight is an issue when it comes to stomping on it from a standstill. Cheapest fix would be to try say a 90-92mm nozzle and step back up to the 95 when you put the bullet in.

[tmack]

Hi there, I have a 4.8m alloy boat running an LS1 and 773 unit, 19 Degree Scott Bullet and 2 Stainless 22 Degree Flopro impellors and a 102mm nozzle. Cruises at 2800rpm and 4400rpm wot. Leaps out of the water and no slippage. Don't know what top speed is as was put together to lift a load and cruise, wasn't interested in speed

[Gonzo7]

Thanks tmack.
Bobcat78 hooked me up with a south Canterbury 19deg bullet & now it holds on nicely. Jumps on the plane quickly for a big boat. Now I can carry on with the rest of the upgrades. It's never-ending...
But I love tinkering